INTERPOLYMER COMPLEX FORMATION THROUGH HYDROGEN BONDING: INTERACTIONS BETWEEN POLYACRYLIC ACID OR ACRYLIC AND COPOLYMERS AND NONIONIC POLYBASES

THE INTERACTIONS BETWEEN WEAK POLYACIDS AND NONIONIC POLYBASES WERE STUDIED, AT DILUTE AQUEOUR SOLUTIONS AND SMALL IONIC STRENGTH. THE POLYACIDS WERE THE POLY(ACRYLIC ACID) AND THE COPOLYMERS OF ACRYLIC ACID WITH N-ISOPROPYLACRYMIDE OR NEGATIVELY CHARGED MONOMERS. THE POLYBASES WERE POLY(ETHYLENEGLYCOL), POLYACRYLAMIDE, POLY(N-ISOPROPYLACRYLAMIDE), POLY(VINYL ALCOHOL) AND VILYLALCOHOLCOPOLYMERS WITH VINYLACETATE. THE STUDY WAS PERFORMED USING VISCOMETRY AND POTENTIOMETRY. IN ADDITION, WE USED TURBIDIMETRY, TO STUDY THE ACRYLIC ACID COPOLYMERS WITH N-ISOPROPYLACRYLAMIDE, AND FLUORESCENCE, TO STUDY THE INTERACTIONS BETWEEN THE POLYACIDS AND NONIONIC SURFACTANTS. VISCOMETRY WAS BASED ON THE ISOTONIC DILUTION METHOD OF POLYELECTROLYTES, THAT ALLOWS THE DETERMINATION OF THE INTRINSIC VISCOSITY AND THE HUGGINS COEFFICIENT OF POLYACIDS AT CONSTANT IONIC STRENGTH AND CONSTANT PH CONDITIONS. POTENSIOMETRY WAS PERFORMED AT THE SAME OR VISCOMETRY CONDIDIONS. IN MOST CASES, IT WAS POSSIBLE TO DETERMINE THE APPARENT COMPLEXATION CONSTANTS OF THE INTERPOLYMER COMPLEXES, THAT WERE FOUND NOT TO BE DEPENDENT ON THE COMPOSITION OF THE CORRESPONDING POLYMER MIXTURES. IT WAS FOUND THAT THE COMPLEXATION ABILITY OF THE POLYACIDS DECREASES WITH INCREASING NUMBER OF GROUPS UNABLE TO FORM HYDROGEN BONDS WITH THE POLYBASES. FURTHERMORE, IT WAS POSSIBLE TO COMPARE THE NONIONIC POLYBASES, ACCORDING TO THE STABILITY OF THE INTERPOLYMER COMPLEXES THAT THEY FORM WITH POLY(ACRYLIC ACID).ΜΕΛΕΤΗΘΗΚΑΝ ΟΙ ΑΛΛΗΛΕΠΙΔΡΑΣΕΙΣ ΜΕΤΑΞΥ ΑΣΘΕΝΩΝ ΠΟΛΥΟΞΕΩΝ ΚΑΙ ΜΗ ΙΟΝΤΙΚΩΝ ΠΟΛΥΒΑΣΕΩΝ, ΣΕ ΑΡΑΙΑ ΥΔΑΤΙΚΑ ΔΙΑΛΥΜΑΤΑ ΚΑΙ ΜΙΚΡΗ ΙΟΝΤΙΚΗ ΙΣΧΥ. ΤΑ ΠΟΛΥΟΞΕΑ ΗΤΑΝ ΤΟ ΠΟΛΥΑΚΡΥΛΙΚΟ ΟΞΥ ΚΑΙ ΤΑ ΣΥΜΠΟΛΥΜΕΡΗ ΤΟΥ ΑΚΡΥΛΙΚΟΥ ΟΞΕΟΣ ΜΕ Ν-ΙΣΟΠΡΟΠΥΛΑΚΡΥΛΑΜΙΔΙΟ Η ΜΕ ΑΡΝΗΤΙΚΑ ΦΟΡΤΙΣΜΕΝΑ ΜΟΝΟΜΕΡΗ. ΟΙ ΠΟΛΥΒΑΣΕΙΣ ΗΤΑΝ Η ΠΟΛΥΑΙΘΥΛΕΝΟΓΛΥΚΟΛΗ, ΤΟ ΠΟΛΥΑΚΡΥΛΑΜΙΔΙΟ, ΤΟ ΠΟΛΥ(Ν-ΙΣΟΠΡΟΠΥΛΑΚΡΥΛΑΜΙΔΙΟ), Η ΠΟΛΥΒΙΝΥΛΙΚΗ ΑΛΚΟΟΛΗ ΚΑΙ ΣΥΜΠΟΛΥΜΕΡΗ ΤΗΣ ΒΙΝΥΛΙΚΗΣ ΑΛΚΟΟΛΗΣ ΜΕ ΟΞΙΚΟ ΒΙΝΥΛΕΣΤΕΡΑ. Η ΜΕΛΕΤΗ ΕΓΙΝΕΜΕ ΤΙΣ ΜΕΘΟΔΟΥΣ ΤΗΣ ΙΞΩΔΟΜΕΤΡΙΑΣ ΚΑΙ ΤΗΣ ΠΟΤΕΝΣΙΟΜΕΤΡΙΑΣ. ΑΚΟΜΗ, ΧΡΗΣΙΜΟΠΟΙΗΘΗΚΕ Η ΘΟΛΟΜΕΤΡΙΑ, ΓΙΑ ΤΗ ΜΕΛΕΤΗ ΤΩΝ ΣΥΜΠΟΛΥΜΕΡΩΝ ΤΟΥ ΑΚΡΥΛΙΚΟΥ ΟΞΕΟΣ ΜΕ Ν-ΙΣΟΠΡΟΠΥΛΑΚΡΥΛΑΜΙΔΙΟ ΚΑΙ Η ΦΘΟΡΙΣΜΟΜΕΤΡΙΑ ΓΙΑ ΤΗ ΜΕΛΕΤΗ ΤΩΝ ΑΛΛΗΛΕΠΙΔΡΑΣΕΩΝ ΤΩΝΠΟΛΥΟΞΕΩΝ ΜΕ ΜΗ ΙΟΝΤΙΚΕΣ ΕΠΙΦΑΝΕΙΑΚΕΣ ΕΝΕΡΓΕΣ ΕΝΩΣΕΙΣ. Η ΙΞΩΔΟΜΕΤΡΙΑ ΒΑΣΙΣΤΗΚΕ ΣΤΗ ΜΕΘΟΔΟ ΤΗΣ ΙΣΟΙΟΝΤΙΚΗΣ ΑΡΑΙΩΣΗΣ ΤΩΝ ΠΟΛΥΗΛΕΚΤΡΟΛΥΤΩΝ, ΠΟΥ ΕΠΙΤΡΕΠΕΙ ΤΟΝΠΡΟΣΔΙΟΡΙΣΜΟ ΤΟΥ ΕΣΩΤΕΡΙΚΟΥ ΙΞΩΔΟΥΣ ΚΑΙ ΤΗΣ ΣΤΑΘΕΡΑΣ HUGGINS ΤΩΝ ΠΟΛΥΟΞΕΩΝ ΣΕ ΣΥΝΘΗΚΕΣ ΣΤΑΘΕΡΗΣ ΙΟΝΤΙΚΗΣ ΙΣΧΥΟΣ ΚΑΙ ΣΤΑΘΕΡΟΥ PH. Η ΠΟΤΕΝΣΙΟΜΕΤΡΙΑ ΠΡΑΓΜΑΤΟΠΟΙΗΘΗΚΕ ΣΕ ΣΥΝΘΗΚΕΣ ΠΑΡΟΜΟΙΕΣ ΜΕ ΤΗΣ ΙΞΩΔΟΜΕΤΡΙΑΣ ΚΑΙ ΟΔΗΓΗΣΕ ΣΤΟΝ ΠΡΟΣΔΙΟΡΙΣΜΟ ΤΩΝ ΦΑΙΝΟΜΕΝΩΝ ΣΤΑΘΕΡΩΝ ΣΧΗΜΑΤΙΣΜΟΥ ΤΩΝ ΔΙΑΠΟΛΥΜΕΡΩΝ ΣΥΜΠΛΟΚΩΝ, ΟΙ ΟΠΟΙΕΣ, ΣΕ ΠΟΛΛΕΣ ΠΕΡΙΠΤΩΣΕΙΣ, ΒΡΕΘΗΚΑΝ ΑΝΕΞΑΡΤΗΤΕΣ ΤΗΣ ΣΥΣΤΑΣΗΣ ΤΩΝ ΜΙΓΜΑΤΩΝ. ΒΡΕΘΗΚΕΠΩΣ Η ΣΥΜΠΛΟΚΟΠΟΙΗΤΙΚΗ ΙΚΑΝΟΤΗΤΑ ΤΩΝ ΠΟΛΥΟΞΕΩΝ ΜΕΙΩΝΕΤΑΙ ΜΕ ΤΗΝ ΑΥΞΗΣΗ ΤΩΝ ΟΜΑΔΩΝ ΠΟΥ ΔΕΝ ΜΠΟΡΟΥΝ ΝΑ ΣΧΗΜΑΤΙΣΟΥΝ ΔΕΣΜΟΥΣ ΥΔΡΟΓΟΝΟΥ ΜΕ ΤΙΣ ΑΝΤΙΣΤΟΙΧΕΣ ΠΟΛΥΒΑΣΕΙΣ. ΕΠΙΠΛΕΟΝ, ΕΓΙΝΕ ΔΥΝΑΤΗ Η ΚΑΤΑΤΑΞΗ ΤΩΝ ΠΟΛΥΒΑΣΕΩΝ ΜΕ ΚΡΙΤΗΡΙΟ ΤΗΝ ΙΣΧΥ ΤΩΝ ΣΥΜΠΛΟΚΩΝ ΠΟΥ ΣΧΗΜΑΤΙΖΟΥΝ ΜΕ ΤΟ ΠΟΛΥΑΚΡΥΛΙΚΟ ΟΞΥ

Rheological study of semidilute aqueous solutions of a thermoassociative copolymer

International audienc

pH-Responsive Emission of Novel Water-Soluble Polymeric Iridium(III) Complexes

The synthesis and characterization of water-soluble copolymers containing N,N-dimethylacrylamide (DMAM) and a vinylic monomer containing an Iridium(III), Ir(III), complex substituted with the quinoline-based unit 2-(pyridin-2-ylo)-6-styrene-4-phenylquinoline (VQPy) as ligand are reported. These copolymers were prepared through pre- or post-polymerization complexation of Ir(III) with the VQPy units. The first methodology led to copolymer P1 having fully complexed VQPy units, whereas the latter methodology allowed the preparation of terpolymers containing free and Ir(III)-complexed VQPy units (copolymer P2). The optical properties of the copolymers were studied in detail through UV-Vis and photoluminescence spectroscopy in aqueous solution. It is shown that the metal-to-ligand charge transfer (ΜLCT) emission is prevailing in the case of P1, regardless of pH. In contrast, in the case of terpolymer P2 the MLCT emission of the Ir(III) complex is combined with the pH-responsive emission of free VQPy units, leading to characteristic pH-responsive color changes under UV illumination in the acidic pH region

Hydrogen-Bonded Interpolymer Complexes Soluble at Low pH

Noncovalent interactions play key roles in many natural processes leading to the self-assembly of molecules with the formation of supramolecular structures. One of the most important forces responsible for self-assembly is hydrogen bonding, which also plays an important role in the self-assembly of synthetic polymers in aqueous solutions. Proton-accepting polymers can associate with proton-donating polymers via hydrogen bonding in aqueous solutions and form polymer-polymer or interpolymer complexes. There has been an increased interest among researchers in hydrogen-bonded interpolymer complexes since the first pioneering papers were published in the early 1960s. Several hundred research papers have been published on various aspects of complex formation reactions in solutions and interfaces, properties of interpolymer complexes and their potential applications. This book focuses on the latest developments in the area of interpolymer complexation via hydrogen bonding. It represents a collection of original and review articles written by recognized experts from Germany, Greece, Kazakhstan, Poland, Romania, Russia, UK, Ukraine, and the USA. It highlights many important applications of interpolymer complexes, including the stabilization of colloidal systems, pharmaceuticals, and nanomaterials

A Library of Quinoline-Labeled Water-Soluble Copolymers with pH-Tunable Fluorescence Response in the Acidic pH Region

A series of quinoline-labeled water-soluble copolymers, synthesized through free radical copolymerization of vinyl-modified quinoline derivatives with water-soluble monomers such as the nonionic <i>N</i>,<i>N</i>-dimethyl­acrylamide (DMAM), the anionic sodium 2-acrylamido­methylpropane­sulfonate (AMPSNa), and the cationic methacryl­amidopropyl­trimethyl­ammonium chloride (MAPTAC), are investigated in the present work. As a result of the protonization/deprotonization equilibrium of the quinoline unit, the optical properties (absorption and, more important, emission of light) of these copolymers are controlled by the pH of the surrounding environment. In fact, the emitted light of the quinoline group changes from blue to green upon decreasing pH. It is shown that this pH-controlled color change can be tuned by the nature of the polymer chain (anionic, nonionic, or cationic) or the existence of substituents (such as cyanophenyl or perfluoro­phenyl groups), giving rise to a library of pH-responding quinoline-labeled materials that cover almost the entire acidic pH region

Comparative Assessment of the Dyeing Process for Pristine and Modified Cotton Fabrics towards the Reduction of the Environmental Fingerprint

Though an important and chronic source of dyes released to the environment, the determination of the release of dyes that occurs during household or industrial washing is usually disregarded. The main scope of this study is to reveal the extent of dye release through washing, and to understand if the modification of cotton fabrics with cationic polymers could reduce it. Modified cotton fabrics, dyed with Acid Blue 281 (AB) or by a mixture of the reactive dyes Novacron Yellow S-3R (NY), Novacron Ruby S-3B (NR) and Novacron Dark Blue S-GL (NDB), underwent a certified washing process. The dyed fabrics were analyzed colorimetrically, while the washing waters were analyzed spectroscopically, via UV/Vis absorption and surface enhanced Raman scattering (SERS). In the modified fabrics dyed with the acid dye, an increased dye uptake was noticed that exhibited a color intensity of K/S~16, compared to K/S~0.45 of the unmodified fabrics. The corresponding normalized dye release (dye concentration/color intensity factor) in the wash water was ~1.6 for the modified fabrics, compared to ~6.5 in the case of the unmodified fabrics, indicating the significance of cotton modification on both the dye uptake and dye release during washing. In the fabrics dyed with a mixture of selected reactive dyes, the color uptake of modified (K/S~10) was also increased compared with unmodified fabrics (K/S~4.5). An important observation, is that in the case of the dyeing of the reactive dyes mixture, a selectivity on the part of the dye uptake was noticed, since the contribution of NY (yellow) is higher compared to that of the blue (positive value of color indicator coordinate (b)); however, this also resulted in an increased NY dye release during washing. The findings of this study could contribute to the dye release problem control due to fabric washing, and to the understanding of any potential selectivity on the part of dye&ndash;cotton interactions

Comparative Assessment of the Dyeing Process for Pristine and Modified Cotton Fabrics towards the Reduction of the Environmental Fingerprint

Though an important and chronic source of dyes released to the environment, the determination of the release of dyes that occurs during household or industrial washing is usually disregarded. The main scope of this study is to reveal the extent of dye release through washing, and to understand if the modification of cotton fabrics with cationic polymers could reduce it. Modified cotton fabrics, dyed with Acid Blue 281 (AB) or by a mixture of the reactive dyes Novacron Yellow S-3R (NY), Novacron Ruby S-3B (NR) and Novacron Dark Blue S-GL (NDB), underwent a certified washing process. The dyed fabrics were analyzed colorimetrically, while the washing waters were analyzed spectroscopically, via UV/Vis absorption and surface enhanced Raman scattering (SERS). In the modified fabrics dyed with the acid dye, an increased dye uptake was noticed that exhibited a color intensity of K/S~16, compared to K/S~0.45 of the unmodified fabrics. The corresponding normalized dye release (dye concentration/color intensity factor) in the wash water was ~1.6 for the modified fabrics, compared to ~6.5 in the case of the unmodified fabrics, indicating the significance of cotton modification on both the dye uptake and dye release during washing. In the fabrics dyed with a mixture of selected reactive dyes, the color uptake of modified (K/S~10) was also increased compared with unmodified fabrics (K/S~4.5). An important observation, is that in the case of the dyeing of the reactive dyes mixture, a selectivity on the part of the dye uptake was noticed, since the contribution of NY (yellow) is higher compared to that of the blue (positive value of color indicator coordinate (b)); however, this also resulted in an increased NY dye release during washing. The findings of this study could contribute to the dye release problem control due to fabric washing, and to the understanding of any potential selectivity on the part of dye–cotton interactions

Polymeric Antimicrobial Coatings Based on Quaternary Ammonium Compounds

Biocidal coatings that are based on quaternized ammonium copolymers were developed after blending and crosslinking and studied as a function of the ratio of reactive groups and the type of biocidal groups, after curing at room temperature or 120 °C. For this purpose, two series of copolymers with complementary reactive groups, poly(4-vinylbenzyl chloride-co-acrylic acid), P(VBC-co-AAx), and poly(sodium 4-styrenesulfonate-co-glycidyl methacrylate), P(SSNa-co-GMAx), were synthesized via free radical copolymerization and further modified resulting in covalently bound (4-vinylbenzyl dimethylhexadecylammonium chloride, VBCHAM) and electrostatically attached (hexadecyltrimethylammonium 4-styrene sulfonate, SSAmC16) units. The crosslinking reaction between the carboxylic group of acrylic acid (AA) and the epoxide group of glycidyl methacrylate (GMA) of these copolymers led to the stabilization of the coatings through reactive blending. The so developed coatings were cured at room temperature and 120 °C, and then immersed in ultra-pure water and aqueous NaCl solutions at various concentrations for a time period up to three months. Visual inspection of the integrity of the materials coated onto glass slides, gravimetry, scanning electron microscopy (SEM) characterization, as well as the determination of total organic carbon (TOC) and total nitrogen (TN) of the solutions, were used to investigate the parameters affecting the release of the materials from the coatings based on these systems. The results revealed that curing temperature, complementary reactive groups’ content, and type of antimicrobial species control the release levels and the nature of releasable species of these environmentally-friendly antimicrobial coatings

Room-Temperature Self-Healable Blends of Waterborne Polyurethanes with 2-Hydroxyethyl Methacrylate-Based Polymers

The design of self-healing agents is a topic of important scientific interest for the development of high-performance materials for coating applications. Herein, two series of copolymers of 2-hydroxyethyl methacrylate (HEMA) with either the hydrophilic N,N-dimethylacrylamide (DMAM) or the epoxy group-bearing hydrophobic glycidyl methacrylate were synthesized and studied as potential self-healing agents of waterborne polyurethanes (WPU). The molar percentage of DMAM or GMA units in the P(HEMA-co-DMAMy) and P(HEMA-co-GMAy) copolymers varies from 0% up to 80%. WPU/polymer composites with a 10% w/w or 20% w/w copolymer content were prepared with the facile method of solution mixing. Thanks to the presence of P(HEMA-co-DMAMy) copolymers, WPU/P(HEMA-co-DMAMy) composite films exhibited surface hydrophilicity (water contact angle studies), and tendency for water uptake (water sorption kinetics studies). In contrast, the surfaces of the WPU/P(HEMA-co-GMAy) composites were less hydrophilic compared with the WPU/P(HEMA-co-DMAMy) ones. The room-temperature, water-mediated self-healing ability of these composites was investigated through addition of water drops on the damaged area. Both copolymer series exhibited healing abilities, with the hydrophilic P(HEMA-co-DMAMy) copolymers being more promising. This green healing procedure, in combination with the simple film fabrication process and simple healing triggering, makes these materials attractive for practical applications